Long short-term memory (LSTM) [1]} is an important ingredient for modern deep RNN architectures. The FG-LSTM extends the LSTM model by adding a new feature gate \(s_t\) , and the Fig. REF  shows the FG-LSTM model. The \(x_t\)  is the input features at time \(t\) , and others are basically consistent with ordinary LSTM. The feature gate has two factors: a feature filter and a time gate.
